Genotypic Variation for Resistance to Preharvest Sprouting in Soybean1

Preharvest sprouting in soybean [Glycine max (L.) Merr.] can reduce seed quality and germination. To determine the amount of genotypic variation for resistance to preharvest sprouting, the percentage of pods ruptured by sprouting seed (PR) and pod rupture adjusted for initial seed germination (APR) were measured on 40 genotypes for 3 years. The pods were produced in the field and screened for resistance in the greenhouse by using a mist chamber. Pods were misted for 4‐rain periods 22 times/ day for 7 days. Genotypic variation within maturity groups was found for PR, APR, post‐treatment seed germination (PTSG), and post‐treatment seed quality. Genotypes with the most resistance to preharvest sprouting were: D65‐8232 (impermeable seed coat) and ‘Hale 3’, Maturity Group (MG) V; ‘Lancer’ ‘Tracy’, MG VI; ‘McNair 800’, MG VII; and ‘Dowling’, MG VIII. The partial correlation coefficient, with the effect of year and maturity removed, between APR and PTSG was negative (r = −0.39). Resistance to preharvest sprouting was associated with slower water uptake by seed. The presence of pubescence on the pod was also associated with less preharvest sprouting.